What color is a stop sign?

Answer: B — Red

A stop sign is a traffic sign used to indicate that drivers must stop at the designated intersection. It is seen as a symbol of authority and is typically used to control traffic flow. This sign is most commonly colored red to grab a driver's attention and to represent the universal color for "stop" or danger. Therefore, the other options - blue, white, and silver - are incorrect because they do not have the same association or visual impact as the color red.